diff --git a/handout/diagrams/halfspaces.tex b/handout/diagrams/halfspaces.tex
index 580d2bb..1675e5f 100644
--- a/handout/diagrams/halfspaces.tex
+++ b/handout/diagrams/halfspaces.tex
@@ -7,7 +7,7 @@
 
     \draw[
         fill,
-        red
+        gray
     ] (-2, -3) -- (-2,-4) -- (2,-6) -- (4.3,-6) -- (4.3,-4) -- cycle;
 
     \draw[
@@ -17,12 +17,12 @@
 
     \draw[
         fill,
-        blue
+        darkgray
     ]  (1.7,-2) circle (15pt);
 
     \draw[
         fill,
-        blue
+        darkgray
     ]  (0.4,-4.2) circle (15pt);
 
     \node (fu) at (1.4,-1) {\LARGE $f_u$ $(+)$};
diff --git a/handout/handout.tex b/handout/handout.tex
index e03f4be..400a560 100644
--- a/handout/handout.tex
+++ b/handout/handout.tex
@@ -143,13 +143,13 @@ Given this function and a set of target images the inverse rendering problem can
 \begin{figure}[h]
     \centering
     \subfloat[initial guess]{
-        \includegraphics[width=0.3\linewidth]{../presentation/img/results/guess.png}
+        \includegraphics[width=0.3\linewidth]{../presentation/img/results/guess-bw.png}
     }
     \subfloat[optimized result]{
-        \includegraphics[width=0.3\linewidth]{../presentation/img/results/result.png}\label{fig:result_image}
+        \includegraphics[width=0.3\linewidth]{../presentation/img/results/result-bw.png}\label{fig:result_image}
     }
     \subfloat[target]{
-        \includegraphics[width=0.3\linewidth]{../presentation/img/results/photo.png}
+        \includegraphics[width=0.3\linewidth]{../presentation/img/results/photo-bw.png}
     }
     \caption{A generic example for how differentiable ray tracing can be used to approximate a solution for the inverse rendering problem.}\label{fig:inverse_rendering_example}
 \end{figure}
diff --git a/presentation/img/results/guess-bw.png b/presentation/img/results/guess-bw.png
new file mode 100644
index 0000000..12b06d7
Binary files /dev/null and b/presentation/img/results/guess-bw.png differ
diff --git a/presentation/img/results/photo-bw.png b/presentation/img/results/photo-bw.png
new file mode 100644
index 0000000..4acd07a
Binary files /dev/null and b/presentation/img/results/photo-bw.png differ
diff --git a/presentation/img/results/result-bw.png b/presentation/img/results/result-bw.png
new file mode 100644
index 0000000..7f8a0a8
Binary files /dev/null and b/presentation/img/results/result-bw.png differ